Vegetation and climate history of Quebec’s mixed boreal forest suggests greater abundance of temperate species during the early- and mid-Holocene

Botany ◽  
2018 ◽  
Vol 96 (7) ◽  
pp. 437-448 ◽  
Author(s):  
Émilie Larochelle ◽  
Martin Lavoie ◽  
Pierre Grondin ◽  
Pierre-Luc Couillard
Keyword(s):  
Boreal Forests ◽  
Regional Scale ◽  
Plant Macrofossils ◽  
Habitat Characteristics ◽  
Temperate Species ◽  
White Pine ◽  
Yellow Birch ◽  
Climate History ◽  
History Of ◽  
Suitable Habitats

Today, scattered disjunct stands of two temperate species, yellow birch and white pine, are present north of their continuous distributional range in southern Quebec (Canada) at topographical locations that offer protection from severe fires. This study tested whether these species had populations more numerous and widespread millennia ago when the climate was presumably warmer. Specifically, this research involved the analyses of pollen, plant macrofossils, and charcoal fragments of two sites within the western part of Quebec’s balsam fir – paper birch bioclimatic domain: a forest humus deposit from a yellow birch stand (local scale), and a peatland (regional scale). Fossil data suggest that white pine was more abundant regionally between 7500 and 5000 cal. BP, before coming rare under subsequent cooler conditions. Likewise, yellow birch was more abundant regionally between 7700 and 1500 cal BP. Its subsequent decline and the local disappearance of white pine by ∼200 cal. BP may both be explained by the severe fires that occurred in recent centuries, as well as the rarity of suitable habitats for these species. The sustained presence of temperate species in mixed boreal forests is the result of the combined action of climate, natural disturbances and habitat characteristics.

History of late- and post-glacial vegetation and disturbance around Upper South Branch Pond, northern Maine

1986 ◽  
Vol 64 (9) ◽  
pp. 1977-1986 ◽  
Author(s):  
R. Scott Anderson ◽  
Ronald B. Davis ◽  
Norton G. Miller ◽  
Robert Stuckenrath
Keyword(s):  
Sediment Cores ◽  
Plant Macrofossils ◽  
White Pine ◽  
Yellow Birch ◽  
Moss Species ◽  
Hemlock Decline ◽  
Shrub Tundra ◽  
History Of ◽  
Mineral Soils ◽  
Upper South

The changing character of vegetation and the effects of disturbance on vegetation are inferred from pollen, plant macrofossils, charcoal, and microlepidopteran larvel head capsules in sediment cores from Upper South Branch Pond, Maine. Following deglaciation 12 500 – 12 000 years ago, a herb–shrub tundra developed which included moss species characteristic of calcareous, mineral soils. Fire and infestation by microlepidopterans were unimportant initially but became important upon arrival of spruce, paper birch, balsam fir, white pine, and tamarack trees (ca. 10 200 – 9500 years BP). Fires were infrequent in the watershed between 7500 and 5000 years BP. The relatively stable forests of this period, dominated by hemlock and yellow birch, grew in what may have been the moistest part of the Holocene. The maximum postglacial abundance of microlepidopteran larvae is centered around the hemlock decline (ca. 4800 years BP). Subsequently, the forest was composed largely of deciduous trees and white pine. Fire incidence was greater, and fewer fossils of microlepidoptera were deposited. Lack of major disturbances between ca. 3300 and 2600 years BP coincided with increases in hemlock, tamarack, yellow birch, and arbor vitae. Increases in boreal conifers began by about 1700 years ago, suggesting cooler, and perhaps wetter, climate. An increase in microlepidoptera accompanied the recent expansion of boreal conifers.

Postglacial vegetation, fire, and climate history of the Siskiyou Mountains, Oregon, USA

2005 ◽  
Vol 64 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Christy E. Briles ◽  
Cathy Whitlock ◽  
Patrick J. Bartlein
Keyword(s):  
Environmental History ◽  
Fire Regime ◽  
Regional Scale ◽  
Natural Disturbance ◽  
High Elevation ◽  
Early Holocene ◽  
Climate History ◽  
Fire Activity ◽  
History Of ◽  
Siskiyou Mountains

AbstractThe forests of the Siskiyou Mountains are among the most diverse in North America, yet the long-term relationship among climate, diversity, and natural disturbance is not well known. Pollen, plant macrofossils, and high-resolution charcoal data from Bolan Lake, Oregon, were analyzed to reconstruct a 17,000-yr-long environmental history of high-elevation forests in the region. In the late-glacial period, the presence of a subalpine parkland of Artemisia, Poaceae, Pinus, and Tsuga with infrequent fires suggests cool dry conditions. After 14,500 cal yr B.P., a closed forest of Abies, Pseudotsuga, Tsuga, and Alnus rubra with more frequent fires developed which indicates more mesic conditions than before. An open woodland of Pinus, Quercus, and Cupressaceae, with higher fire activity than before, characterized the early Holocene and implies warmer and drier conditions than at present. In the late Holocene, Abies and Picea were more prevalent in the forest, suggesting a return to cool wet conditions, although fire-episode frequency remained relatively high. The modern forest of Abies and Pseudotsuga and the present-day fire regime developed ca. 2100 cal yr B.P. and indicates that conditions had become slightly drier than before. Sub-millennial-scale fluctuations in vegetation and fire activity suggest climatic variations during the Younger Dryas interval and within the early Holocene period. The timing of vegetation changes in the Bolan Lake record is similar to that of other sites in the Pacific Northwest and Klamath region, and indicates that local vegetation communities were responding to regional-scale climate changes. The record implies that climate-driven millennial- to centennial-scale vegetation and fire change should be considered when explaining the high floristic diversity observed at present in the Siskiyou Mountains.

Late Quaternary vegetation and climate history of a perennial river canyon in the Río Salado basin (22°S) of Northern Chile

2006 ◽  
Vol 65 (3) ◽  
pp. 450-466 ◽  
Author(s):  
Claudio Latorre ◽  
Julio L. Betancourt ◽  
Mary T.K. Arroyo
Keyword(s):  
Late Quaternary ◽  
Plant Macrofossils ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Northern Chile ◽  
Climate History ◽  
Emerging Trends ◽  
History Of ◽  
Bolivian Altiplano ◽  
Vegetation And Climate

AbstractPlant macrofossils from 33 rodent middens sampled at three sites between 2910 and 3150 m elevation in the main canyon of the Río Salado, northern Chile, yield a unique record of vegetation and climate over the past 22,000 cal yr BP. Presence of low-elevation Prepuna taxa throughout the record suggests that mean annual temperature never cooled by more than 5°C and may have been near-modern at 16,270 cal yr BP. Displacements in the lower limits of Andean steppe and Puna taxa indicate that mean annual rainfall was twice modern at 17,520–16,270 cal yr BP. This pluvial event coincides with infilling of paleolake Tauca on the Bolivian Altiplano, increased ENSO activity inferred from a marine core near Lima, abrupt deglaciation in southern Chile, and Heinrich Event 1. Moderate to large increases in precipitation also occurred at 11,770–9550 (Central Atacama Pluvial Event), 7330–6720, 3490–2320 and at 800 cal yr BP. Desiccation occurred at 14,180, 8910–8640, and 4865 cal yr BP. Compared to other midden sites in the region, early Holocene desiccation seems to have happened progressively earlier farther south. Emerging trends from the cumulative midden record in the central Atacama agree at millennial timescales with improved paleolake chronologies for the Bolivian Altiplano, implying common forcing through changes in equatorial Pacific sea-surface temperature gradients.

Late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska

2003 ◽  
Vol 60 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Thomas A. Ager
Keyword(s):  
Boreal Forests ◽  
Vegetation Change ◽  
Late Quaternary ◽  
Land Bridge ◽  
Climate History ◽  
Middle Holocene ◽  
Bering Land Bridge ◽  
Dwarf Birch ◽  
History Of ◽  
Vegetation And Climate

AbstractPollen analysis of a sediment core from Zagoskin Lake on St. Michael Island, northeast Bering Sea, provides a history of vegetation and climate for the central Bering land bridge and adjacent western Alaska for the past ≥30,000 14C yr B.P. During the late middle Wisconsin interstadial (≥30,000–26,000 14C yr B.P.) vegetation was dominated by graminoid-herb tundra with willows (Salix) and minor dwarf birch (Betula nana) and Ericales. During the late Wisconsin glacial interval (26,000–15,000 14C yr B.P.) vegetation was graminoid-herb tundra with willows, but with fewer dwarf birch and Ericales, and more herb types associated with dry habitats and disturbed soils. Grasses (Poaceae) dominated during the peak of this glacial interval. Graminoid-herb tundra suggests that central Beringia had a cold, arid climate from ≥30,000 to 15,000 14C yr B.P. Between 15,000 and 13,000 14C yr B.P., birch shrub-Ericales-sedge-moss tundra began to spread rapidly across the land bridge and Alaska. This major vegetation change suggests moister, warmer summer climates and deeper winter snows. A brief invasion of Populus (poplar, aspen) occurred ca.11,000–9500 14C yr B.P., overlapping with the Younger Dryas interval of dry, cooler(?) climate. During the latest Wisconsin to middle Holocene the Bering land bridge was flooded by rising seas. Alder shrubs (Alnus crispa) colonized the St. Michael Island area ca. 8000 14C yr B.P. Boreal forests dominated by spruce (Picea) spread from interior Alaska into the eastern Norton Sound area in middle Holocene time, but have not spread as far west as St. Michael Island.

Late-Glacial and Postglacial Vegetational History of the Berkshires, Western Massachusetts

1979 ◽  
Vol 12 (3) ◽  
pp. 333-357 ◽  
Author(s):  
Donald R. Whitehead
Keyword(s):  
Boreal Forest ◽  
New England ◽  
Boreal Forests ◽  
Sugar Maple ◽  
Late Glacial ◽  
Analytical Investigation ◽  
Red Maple ◽  
White Pine ◽  
Berkshire County ◽  
History Of

A pollen analytical investigation of the sediments of Berry Pond, Berkshire County, Massachusetts, has demonstrated a sequence of pollen assemblage zones similar to those detected elsewhere in New England. From about 13,000 to 12,000 yr B.P. the vegetation of the region was treeless, probably tundra. By 11,500 yr tundra had been replaced by open boreal forest. Closed boreal forest became dominant by 10,500 yr. Boreal forests were replaced by mixed coniferous and deciduous forests with much white pine about 9600 yr ago. A “northern hardwoods” complex with much hemlock, beech, and sugar maple succeeded the mixed forests 8600 yr ago. Hemlock declined very rapidly approximately 4800 yr ago and was replaced by birch, oak, beech, ash, and red maple. This decline may have been biologically rather than climatically induced. There is a slight maximum of pine (much of it pitch pine) from 4100 to 2600 yr ago, perhaps indicative of warmer and/or drier conditions. There were slight changes in the forests about 1600 yr ago as chestnut immigrated and spruce and larch increased slightly. European land clearance and subsequent land abandonment are detectable in the uppermost levels.

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